China's Economic Prosperity Parallels Rising Stroke Rate (original) (raw)

March 5, 2008 — A rise in ischemic stroke in China is being attributed to growth in the country's economic prosperity over the past 2 decades.

A large, long-term, population-based study showed that from 1984 to 2004 the rate of ischemic stroke in China increased by almost 9%.

The study's lead author, Dong Zhao, MD, PhD, from Beijing Anzhen Hospital, in China, said these changes in China's stroke rate and stroke mortality occurred during a time of rapid economic development and growth in the country that greatly changed people's lifestyles and healthcare.

"The changes in patterns of stroke have raised new challenges and the need to adjust priorities to prevent stroke in China," said Dr. Zhao, in a statement from the American Stroke Association.

The study is published online February 28 in Stroke.

Unique Study

According to the study, previous population-based research has suggested a link between poverty and certain stroke characteristics, more hemorrhagic strokes, stroke onset at younger ages, more fatal strokes, and more deaths from stroke than from heart disease.

If this is the case, the authors note, stroke rates should decline during periods of economic prosperity. However, there has been little, if any, research that has tested this hypothesis, making this study the first of its kind.

"No previous data provided prospective and long-term trends on the incidence of stroke and case fatality rate in 1 large population of a developing country as evidence of the epidemiological transition of stroke," said Dr. Zhao, who is also chair of the Council of Epidemiology and Prevention for the World Heart Federation.

To examine the changes in trends of stroke epidemiology during a period of fast economic development in China, researchers used data from the Sino–Monitoring Trends and Determinants in Cardiovascular Disease Project (MONICA)–Beijing, which tracked incidence and mortality rates of stroke and cardiovascular events in Beijing from 1984 to 2004.

Over the study period, 14,585 strokes occurred in individuals aged 25 to 74 years. The analysis revealed an average annual 8.7% increase in ischemic stroke and an average 1.7% decrease in hemorrhagic stroke. However, the overall fatality rates decreased for both types of stroke — 1.7% for hemorrhagic stroke and 0.5% for ischemic stroke. The authors also note the rate of decline was greater during the second decade of follow-up.

In addition, the mean age of onset for stroke was delayed 2.7 years in men and 3.6 years in women. Further, the proportion of individuals with ischemic heart disease increased during the study period.

Major Risk Factors on the Rise

While rates of smoking remained relatively static during the study period, other major risk factors increased substantially, including obesity and hypercholesterolemia. In particular, total fat intake increased from 88.1 g/day in 1983 to 97.4 g/day in 2002.

The investigators also found average blood cholesterols levels increased by 24% from 1984 to 1999. From 1994 to 2002, there was a 97% increase in diabetes prevalence, and obesity in China increased by 13% in urban areas and 85% in rural regions.

"Risk factors have become a new problem and challenge for public health in China," said Dr. Zhao. He added that lack of access to healthcare services, particularly in rural areas, remains "an important barrier to treatment of risk factors for stroke in China."

In an accompanying editorial, Thomas Truelsen, MD, PhD, from the Bispebjerg University Hospital, in Copenhagen, Denmark, and Ruth Bonita, PhD, from the School of Population Health, University of Auckland, in New Zealand, warn that "it is possible that the effects of today's prevalence of risk factors in the Chinese population will reach many years into the future, not only with respect to stroke but also ischemic heart disease. Early prevention through legislation and active public health policy could reduce the potential harmful effects of an improved economy."

The study was funded by the People's Republic of China Ministry of Science and Technology and the Ministry of Health, with additional funding from the World Health Organization and a project from Beijing Municipal Science and Technology Commission.

Stroke. Published online February 28, 2008. Abstract Abstract